Device-to-Device (D2D) communication is a communication scheme for directly transmitting/receiving data between user equipments (UEs) without an evolved NodeB (eNB) by establishing a direct link between UEs. D2D communication may include UE-to-UE and peer-to-peer communication schemes. In addition, D2D communication is applicable to machine-to-machine communication, machine type communication (MTC), etc.
D2D communication is a method considered for reducing the burden of an eNB due to rapidly increasing data traffic. For example, D2D communication can decrease network overload because data is directly exchanged between devices without an eNB, unlike a conventional wireless communication system.
Furthermore, D2D communication can reduce the number of processes of an eNB and power consumption of devices participating in D2D communication, increase data throughput and network capacity, distribute loads, extend cell coverage, etc.